1. Field of the Invention
The present invention relates to a rectangular orthodontic arch wire appliance and a manufacturing method of the rectangular orthodontic arch wire appliance.
2. Description of the Related Art
In the conventional full-banded orthodontic treatment, only aesthetic aspects were emphasized when preparing an arch wire (rectangular arch wire). Therefore, respective teeth were arranged flatly in an elevational view and the arch wire was bent along a dental arch in a plan view.
FIG. 18 shows a conventional arch wire in a plan view. FIG. 19 shows the conventional arch wire in a side view. The left side of the figures is the front of the arch wire.
As explained later, an occlusal surface of the dental arch is not originally flat. As shown by two-dot chain line in FIG. 19, the occlusal surface is curved slightly in an anteroposterior direction. However, respective teeth are initially arranged flatly as shown by solid line.
The teeth are arranged flatly not only for the aesthetic aspects, but also for applying a torque to the arch wire.
FIG. 20 is a rear view of the conventional arch wire. As shown in the figure, in order to give a twisting power to the arch wire, the arch wire should be twisted. If the arch wire is not flat, a shape of the arch wire in a plan view is changed when the rectangular arch wire is twisted.
On the other hand, U.S. Pat. No. 6,276,932 discloses a technology based on a need of such a three-dimensional shape.